Releasable lock means for boom

ABSTRACT

A releasable lock means for holding a boom in a storage position on a support is disclosed herein. The releasable lock means consists of a first member or pin that is carried by the support and a second member or lock ring that is pivoted on the boom and has an opening for receiving the pin. The second member is biased to a first position and engages with the pin as the boom is moved to its storage position to overcome the biasing means. When the opening in the second member and the pin are axially aligned, the biasing means returns the second member to the first position to produce an interlock between the two members. The device also incorporates release means for pivoting the second member and separating the members.

United States Patent 1191 Baker et al.

1451 Nov. 25, 1975 RELEASABLE LOCK MEANS FOR BOOM [75] Inventors: Donald C. Baker, Rosedale; Lloyd A. Brewer, West Terre l-Iaute; Herman J. Maurer, Terre Haute, all of Ind.

[73] Assignee: J. 1. Case Company, Racine, Wis.

22 Filed: May 28, 1974 [21] Appl. No.: 473,703

[52] US. Cl. 214/138 R; 214/130 R 51 Int. c1? E02F 3/32 58 Field of Search 214/130 R, 131, 138 R, 214/138 c, 145, 7-80 [56] References Cited I UNITED STATES PATENTS 2,780,374 2/1957 McElhinney et .11.. 214/780 2,993,608 7/1961 Womble 214/780 3,8I 1,582 5/I974 Shumaker 6t III. 2I4/I30 R FOREIGN PATENTS OR APPLICATIONS Germany 2l4/780 707,393 4/1954 United Kingdom 214/780 Primary Examiner-Robert J. Spar Assistant Examiner-Ross Weaver Attorney, Agent, or FirmDr'essIer, Goldsmith.

Clement & Gordon, Ltd. 1 1

57] ABSTRACT A releasable lockmeans for holding a boom in a storage position on a support is disclosed herein. The releasable lock means consists of a first member or pin that is carried by the support'and a second member or lock ring that is pivoted on the boom'and has an opening for receiving the pin. The second member is biased to a first position and engages with the pin as the boom is moved to its storage position to overcome the biasing means. When the opening in the second memher and the pin are axially aligned, the biasing means returns the second member to the first position to produ ce, an interlock between the two members. The device "also incorporates release means for pivoting the second member and separating-the members.

4 Claims, 4 Drawing Figures US. Patent Nov. 25, 1975 SheetlofZ 3,921,835

US. Patent Nov. 25, 1975 Sheet2of2 3,921,835

RELEASABLE LOCK MEANS FOR BOOM BACKGROUND OF THE INVENTION The present invention relates generally to earthworking implements, such as backhoes.

Most commercially available backhoes consist of a boom that is pivoted on a support or swing tower and an earth-working tool or bucket assembly is pivoted on the free end of the boom. The boom and bucket assembly are pivoted by fluid rams.

One type of such earth-working implement is shown in Long, et al. U.S. Pat. No. 3,376,984. The disclosure of this patent relates to what is referred to as an overcenter boom, that is a boom which can be swung to a transport or storage position that is generally vertical and slightly forward of a vertical axis extending through the pivot axis for the boom on the support. In the Long et al. patent, the boom is held in the transport position by the fluid rams that are utilized to pivot the boom on the support.

It has been found that there are times when it is desirable to positively interlock the boom and its support without relying upon the fluid in the boom rams. In certain instances, it is desirable to hold the boom in the over-center position to permit maximum utilization of fluid power for lifting and swinging pay loads carried by the earth-working tool or bucket assembly.

One type of positive interlocking between the boom and the support is disclosed and claimed in U.S. application Ser. No. 223,688 now U.S. Pat. No. 3,811,582, filed Feb. 4, 1972 and assigned to the assignee of the present invention.

Because of the competitive nature of this industry, manufacturers are constantly striving for improvements which will allow for manufacture of the units of a reduced cost without sacrificing any operative characteristics of the unit.

SUMMARY OF THE INVENTION According to the present invention, a boom is positively locked to a support in a storage or transport position by utilizing a minimum number of parts and relying primarily upon existing equipment that is already part of the unit. The releasable lock means that is utilized to lock the boom on the support automatically moves to the interlock position when the boom is moved to the storage or transport position. The interlock can readily be released from the control console for the unit by manipulation of a single control handle. All of the above is accomplished with very few parts that can readily be incorporated into existing units with minimum modification and cost.

More specifically, the releasable lock means consists of a first member that is fixed to the support and a second member that is carried by the boom and is movable relative thereto. The second member is normally biased to a first position by biasing means and the two members are located so that the second member engages and slides along the first member as the boom is pivoting towards the storage or transport position. The second member has an opening for receiving the first member and the biasing means returns the second member to the first position when the opening and the first member are aligned with each other to interlock the boom and the support. The mechanism also has release means for separating the two members.

According to one aspect of the invention, the first member that forms part of the releasable lock means is the free end of pin means that are normally utilized for mounting the support on a base of a vehicle for pivotal movement about a vertical pivot axis. This pin means is a fixed pin portion that is carried by the support and rotatable on the base so that the pin means remains fixed with respect to the support.

In the specific embodiment, the second member consists of a ring-like structure that is pivotally supported about a horizontal pivot axis on the boom and is biased by an elastomeric member to a first position. The ad vantage of utilizing an elastomeric member is that the member also holds the ring in a substantially fixed position during normal manipulation of the boom.

The specific release means also is a simple structure that consists of a rod supported on a control console carried by the base and having a laterally offset portion aligned with the ring-like structure. The rod can be rotated by the operator in the control console to separate the first and second members from each other. The rod also has means for normally maintaining it in a first position and returning the rod to the first position when the external turning force applied thereto is released.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary side elevational view of a vehicle having an earth-working unit mounted thereon and having the present invention incorporated therein;

FIG. 2 is a fragmentary plan view showing details of the releasable lock means of the present invention;

FIG. 3 is an enlarged fragmentary side elevational view of a portion of the vehicle shown in FIG. I; and

FIG. 4 is a further fragmentary side elevational view showing the boom and support as well as the releasable lock means just prior to moving into an interlock position.

DETAILED DESCRIPTION While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated.

FIG. 1 of the drawings shows a vehicle, generally designated by the reference numeral 10, having an earthworking implement 12 supported thereon. Implement 12 consists of a backhoe which includes a frame or base 14 having Outriggers 16 supported thereon with the frame being attached to or forming a part of the rear end of the vehicle, adjacent an operators station 18. The operators station 18 may be part of the vehicle or may be part of frame 14.

A swing tower or support 20 is pivoted about a vertical axis defined by pivot means or pins 22, which will be described in more detail later, while a boom 24 is supported at its inner end by a horizontal pivot pin 26 on the support or swing tower 20. Boom 24 is pivoted about horizontal pivot axis 26 by a pair of fluid rams 28 (only one being shown) located on opposite sides of the boom with cylinder 30 of the ram secured to the support and the piston rod 32 secured to the boom. The earth-working tool or dipper stick assembly 34 is supported on the outer end of the boom and consists of a member 36 pivoted intermediate its ends on the free end of boom by pivot pin 38 and movement of member 36 is controlled by a fluid ram 40 having its cylinder 42 pivotally supported on a boom adjacent support while piston rod 46 is pivotally supported on one end of the member or dipper stick 36 by a pin 48. A bucket 50 is pivoted on the opposite or outer end of dipper stick 36 by a further fluid ram 52.

During normal operation of the implement or earthworking, the boom is normally maintained rearwardly or to the left of a plane P (FIG. 1) extending vertically through pivot axis 26 and the boom, dipper stick and bucket are manipulated by applying pressurized fluid to opposite ends of fluid rams 28, 40 and 52.

As is discussed in more detail in the above-mentioned Long, et al. patent, when it is desired to move the implement to its over center transport or storage position, fluid rams 28 are manipulated in such a manner that the boom is moved to the opposite side of vertical plane P extending through pivot pin 26. This manner of moving the boom to the transport position is explained in more detail in the Long, et al. patent, which is incorporated herein by reference.

According to the present invention, the boom and support carry releasable lock means that automatically interlock the boom and the support when the boom is moved to the transport or storage position. The releasable lock means consists of two members and one of the members is defined by a portion of the interconnection between the support and the base forming part of the vehicle so that the positive interlock can be accomplished with a minimum number of parts.

More specifically, the releasable lock means includes a first member carried by the support. In the illustrated embodiment, the first member is the upper pin 60 that forms part of pin means 22, which defines the vertical pivot between swing tower or support 20 and base 14. Pin 60 extends upwardly above base 14 and support 20 and has a free end portion 64. One of the aspects of the present invention is the fact that pin 60 is fixed with respect to support 20 and is rotatably journaled in a bearing 62 carried by a portion of base 14, the significance of which will be described later.

The remaining part of releasable lock means includes a second member or ring structure 66 (FIG. 3) that has an opening 67 for receiving pin 60. Second member 66 is supported for movement on a pair of ears that form part of boom 24 by a horizontal pin 70 received through a bushing 72 that is fixedly secured and forms part of the second member or ring-like structure 66. Second member 66 is normally biased to a first position by biasing means 76, interposed between boom 24 and second member 66, which accommodates movement of second member 66 from the first position. Preferably, this biasing means is in the form of an elastomeric or rubber member 78 that has one end connected to a bracket 80 carried by boom 24 and the opposite end connected to a bracket 82 on second member 76. The first position for the second member or ring-like structure 66 is preferably defined by a stop 86 carried by bushing 72 and a further stop 88 fixed to boom 24.

The interlock mechanism between the boom and support also incorporates release means for moving the second member from the solid line first position shown in FIG. 3 to the dotted line or second position also shown in FIG 3. This release means consists of a rod 90 that is rotatably supported in a hub 91 which is fixed to control console 94, forming part of base 14. Rod 90 has an offset portion 92 that is located between base 14 and second member 66 when the rod is in a first released position. Rod 90 has a handle portion 93 located in the control console for the vehicle so that rod 90 can be rotated about an axis defined by hub or sleeve 91 to raise or pivot second member 66 about pivot pin and separate members 66 and 60 from each other.

Preferably, rod is normally held in the first, released position shown in FIGS. 2 and 3 by mechanism which will now be described. The means for normally maintaining the rod 90 in the first position where the offset portion 92 is located below and slightly spaced from the lower surface of ring structure 66, is shown in detail in FIG. 3 and consists of an inclined camming surface on hub 91 and a pin 102 that is carried by rod 90. A coil spring or spring means 104 is located between a pair of washers 106 and 108 respectively carried by hub 91 that has camming surface 102 thereon and rod 90. A further pin 110 is carried by rod 90 and defines an abutment for one washer 108.

' In the normal position, shown in FIG. 3, spring means 104 maintains pin 102 in engagement with camming surface 100 and defines the first position for rod 90. When handle portion 93 is moved, rod 90 is rotated about a fixed axis defined by sleeve 91 and is simultaneously axially shifted with respect to the axis by having pin 100 to ride upwardly along camming surface 100, as viewed in FIG. 3. This will cause compression of coil spring 104 and will move second member 66 from the solid line position shown in FIG. 3 to the dotted line position thereof to separate members 60 and 66. Release of handle portion 93 will automatically cause spring means 104 to return rod 90 and offset portion 92 to the solid line position shown in the drawings.

The operation of the releasable lock means will now be described. As was indicated above, the boom moves across vertical plane P, extending through pivot axis 26 for boom 24 to an over-center transport or storage position that is shown in FIG. 1. When the pin 70, defining the pivot axis for second member 66 is in vertical alignment with plane P, member or plate 66 is in the position that is substantially as illustrated in FIG. 4 of the drawings wherein the lower surface of plate 66 is just slightly above the height of free end portion 64 of pin 60. Continued pivotal movement of boom 24 about pivot axis 26 will cause pin 70 to move along an are about pivot axis 26 and lower the pivot axis with respect to first member or free end portion 64 of pin 60. During this movement, engagement is created between the lower surface of plate 66 and free end portion 64 of pin 60 which overcomes biasing means 76 and causes member 66 to pivot generally to the dotted line position shown in FIG. 3. As opening 67 becomes in general vertical alignment with pin 60, biasing means 76 reacts to move second member 66 to the solid line position shown in FIG. 3. In this position, opening 67 surrounds pin 60 to provide an interlock between boom 24 and support 20. This will hold boom 24 in a transport or storage position with respect to support or swing tower 20 until released by a release means that has been described above.

To release the boom from support 20 for pivotal movement relative thereto, it is only necessary for the operator seated adjacent control console 94 to rotate rod 90 in a clockwise direction which will raise offset portion 92 and pivot member 66 from the solid line to the dotted line position shown in FIG. 3. This will then release boom 24 from support 20 and allow fluid rams 24 to be actuated to move the boom from the transport position by. proper selection of the length of elastomeric member 78.

While a particular interlock means and its operation has been shown and described in connection with an over-center type boom, the same unique arrangement can readily be incorporated into a boom structure wherein the boom never travels across vertical plane P. In such an arrangement, it may be necessary to produce an inclined camming surface on end portion64 of pin 60 so that second member 66 will be pivoted from the first position to a second position while the boom is moving along a path where pivot pin 70 is continually moved upwardly.

What is claimed is:

1. In an earth-working implement having a boom pivoted about a horizontal pivot axis on a support with an earth-working unit pivoted on the free end of said boom, said support being pivoted about a vertical pivot axis on a base with said vertical pivot axis being defined by at least one pin fixed to said support and rotatable on said base, and releasable lock means between said boom and said support, said releasable lock means including a firstmember on one of said support and said boom, a second member on the other of said support and boom, said second member including a ring structure pivoted about a horizontal pivot axis on the other of said support and boom and including an opening within its confines for receiving said first member, said first member being an upper free end portion of said at least one pin, biasing means cooperating with said second member for normally maintaining said second member in a first position and accommodating movement from said first position, said members being positioned so that pivotal movement of said boom to a storage position will produce engagement between said members and cause movement of said second member from said first position, said biasing'means returning said second member to said first position when said first member is aligned with said opening, and release means for moving said second member from said first position and separate said members.

2. An earth-working implement as defined in claim 1, in which said biasing means is an elastomeric member between said boom and said second member and in which said boom has stop means defining said first position.

3. An earth-working implement as defined in claim 1, in which said release means includes a rod rotatably supported about a pivot axis adjacent said support, said rod having a laterally offset portion cooperating with said second member so that rotation of said rod from a first position will move said second member from said first position to separate said members, and means normally maintaining said rod in saidfirst position.

4. An earth-working implement as defined in claim 3, in which said means normally maintaining said rod in said first position includes a fixed camming surface adjacent said rod, a pin carried by said rod, spring means between said rod and said camming surface for maintaining engagement between said pin and said camming surface so that rotation of said rod will move said pin alongsaid camming surface to axially shift said rod and compress said spring means, and release of said rod will cause said spring means to return said rod to said first position. r 

1. In an earth-working implement having a boom pivoted about a horizontal pivot axis on a support with an earth-working unit pivoted on the free end of said boom, said support being pivoted about a vertical pivot axis on a base with said vertical pivot axis being defined by at least one pin fixed to said support and rotatable on said base, and releasable lock means between said boom and said support, said releasable lock means including a first member on one of said support and said boom, a second member on the other of said support and boom, said second member including a ring structure pivoted about a horizontal pivot axis on the other of said support and boom and including an opening within its confines for receiving said first member, said first member being an upper free end portion of said at least one pin, biasing means cooperating with said second member for normally maintaining said second member in a first position and accommodating movement from said first position, said members being positioned so that pivotal movement of said boom to a storage position will produce engagement between said members and cause movement of said second member from said first position, said biasing means returning said second member to said first position when said first member is aligned with said opening, and release means for moving said second member from said first position and separate said members.
 2. An earth-working implement as defined in claim 1, in which said biasing means is an elastomeric member between said boom and said second member and in which said boom has stop means defining said first position.
 3. An earth-working implement as defined in claim 1, in which said release means includes a rod rotatably supported about a pivot axis adjacent said support, said rod having a laterally offset portion cooperating with said second member so that rotation of said rod from a first position will move said second member from said first position to separate said members, and means normally maintaining said rod in said first position.
 4. An earth-working implement as defined in claim 3, in which said means normally maintaining said rod in said first position includes a fixed camming surface adjacent said rod, a pin carried by said rod, spring means between said rod and said camming surface for maintaining engagement between said pin and said camming surface so that rotation of said rod will move said pin along said camming surface to axially shift said rod and compress said spring means, and release of said rod will cause said spring means to return said rod to said first position. 